I have a GB 49 1990 classic with holding plate refrigeration. The two refrigerator boxes hold temp about 40f and the freezer box holds between 0 and 10F. To main these temps required about. 30 minutes morning and evening run time on the generator. The compressor is a Copeland 1.5 hp unit using R404a refrigerant. It has a slow leak requiring a charge about 4 years. The run time lengthen to about 50 minutes before the recharge twice a day.
You said your compressor is running 24/7. Sounds like you need do to recharge your unit and fix a leak. What type of compressor do you have? The do a pretty good job if they are fully charged and the controls are functionable.